Catholic Church in Australia

The Australian Catholic Church or Catholic Church in Australia is part of the worldwide Catholic Church under the spiritual and administrative leadership of the Holy See. From origins as a suppressed, mainly Irish minority in early colonial times, the church has grown to be the largest Christian denomination in Australia, with a culturally diverse membership of around 5,075,907 people, representing about 20% of the overall population of Australia according to the 2021 ABS Census data.

The church is the largest non-government provider of welfare and education services in Australia. Catholic Social Services Australia aids some 450,000 people annually, while the St Vincent de Paul Society's 40,000 members form the largest volunteer welfare network in the country. In 2016, the church had some 760,000 students in more than 1,700 schools.

The church in Australia has five provinces: Adelaide, Brisbane, Melbourne, Perth and Sydney. It has 35 dioceses, comprising geographic areas as well as the military diocese and dioceses for the Chaldean, Maronite, Melkite, Syro-Malabar (St Thomas Christians), and Ukrainian Rites. The national assembly of bishops is the Australian Catholic Bishops Conference (ACBC). There are a further 175 Catholic religious orders operating in Australia, affiliated under Catholic Religious Australia. One Australian has been recognised as a saint by the Catholic Church: Mary MacKillop, who co-founded the Sisters of St Joseph of the Sacred Heart ("Josephite") religious institute in the 19th century.